Alpha Over .png file pixelated after adding it to Video Sequence Editor
In the filter layout, try setting the "Convert to Float" value to True. Also try Enabling "Deinterlace". Put the Text image over your black color and make sure it's blend mode is set to "Alpha".



Your Example Blend files didn't have the text images in them, so I couldn't make sure my advice would help.

It could also be that your text image isn't high enough resolution.